Positive pressure-applying latch mechanism

ABSTRACT

A latch mechanism is provided for latching a field-replaceable unit within an enclosure. The latch mechanism includes a pivotable latch coupled to the field-replaceable unit via a pivot, at a first side of the unit, and a spring member associated with the enclosure. The spring member is engaged by the latch and deflects with rotating of the latch from an open position to a latched position. The pivotable latch includes the first end and a second end, with the pivot being disposed closer to the first end than the second. The deflecting spring member facilitates provision of positive pressure on the unit directed towards a second side of the unit opposite to the first side to facilitate, for example, fixedly coupling a first connector at the second side to a second connector associated with the enclosure when the unit is latched within the enclosure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 15/176,626, filedJun. 8, 2016, and entitled “Positive Pressure-Applying Latch Mechanism”,which is a continuation of U.S. Ser. No. 14/178,395, filed Feb. 12,2014, entitled “Positive Pressure-Applying Latch Mechanism”, whichissued on Aug. 30, 2016, as U.S. Pat. No. 9,433,119 B2. Each of theseapplications is hereby incorporated by reference herein in its entirety.

BACKGROUND

A field-replaceable unit (FRU), also referred to as acustomer-replaceable unit (CRU), may comprise a circuit board, part orassembly that can be readily removed from an electronics enclosure (orchassis), such as a computer, mainframe, or other piece of electronicequipment, and replaced by a user or technician without having to sendthe entire electronics enclosure or system to a repair facility. Forexample, field-replaceable units allow a technician lacking an in-depthproduct knowledge of a particular system to fault isolate and replace afaulty component or unit. Field-replaceable units are not strictlyconfined to computers, but also may comprise part of many higher-endconsumer and commercial electronic products.

As the sophistication and complexity of multi-replaceable unitelectronics in both commercial and consumer industries has increased,many design and manufacturing organizations have expanded the use offield-replaceable units to, for example, input/output devices, controldevices, storage devices, etc. As one example, one or morefield-replaceable units may be employed as input/output, control, orstorage within an electronic system or rack. In such a field-replaceableunit, a first connector associated with the unit couples to a secondconnector associated with the enclosure as the field-replaceable unit isdocked within the enclosure. Positive pressure or force can be appliedon the first connector to the second connector by, for example,mechanical fasteners. However, the use of mechanical fasteners to (forexample) ensure positive force on the connectors requires the use oftools, which adds complexity to the field replaceability of thefield-replaceable unit.

SUMMARY

The shortcomings of the prior art are overcome and additional advantagesare provided through the provision, in one aspect, of a method, whichincludes providing a pivotable latch coupled to a unit via a pivot. Thepivot is disposed at a first side of the unit, and the unit is to belatched within an enclosure. The method further includes providing aspring member associated with the enclosure, and separate from thepivotable latch. The spring member is contacted by, and has a tensionforce applied thereto by, a first end of the pivotable latch withrotating of the latch from an open position to a latched position duringlatching of the unit within the enclosure. The pivotable latch includesthe first end and a second end, and the pivot is disposed closer to thefirst end than the second end thereof. Rotating of the latch from theopen position to the latched position during latching of the unit withinthe enclosure results in the latch contacting the spring member, andslidably deflecting a first end and a second end of the spring memberaway from each other in opposite directions, thereby facilitatingprovision of a positive pressure on the unit by the pivotable latchdirected towards a second side of the unit opposite the first sidethereof with latching of the unit within the enclosure.

In a further aspect, a method of facilitating secure latching of afield-replaceable unit (FRU) within an enclosure is provided. The methodincudes providing a latch mechanism to facilitate secure latching of thefield-replaceable unit within the enclosure. The latch mechanismincludes a pivotable latch coupled to the field-replaceable unit via apivot, where the pivot is disposed at a first side of thefield-replaceable unit. Further, the latch mechanism includes a springmember associated with the enclosure and separate from the pivotablelatch. The spring member is contacted by, and has a tension forceapplied thereto by, a first end of the pivotable latch with rotating ofthe latch from an open position to a latched position during latching ofthe field-replaceable unit within the enclosure. The pivotable latchincludes the first end and a second end, and the pivot is disposedcloser to the first end than the second end thereof. The rotating of thelatch from the open position to the latched position during latching ofthe field-replaceable unit within the enclosure results in the latchcontacting the spring member, and slidably deflecting a first end and asecond end of the spring member away from each other in oppositedirections, thereby facilitating provision of a positive pressure on thefield-replaceable unit by the pivotable latch directed towards a secondside of the field-replaceable unit opposite the first side thereof withlatching of the field-replaceable unit within the enclosure.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more aspects of the present invention are particularly pointedout and distinctly claimed as examples in the claims at the conclusionof the specification. The foregoing and other objects, features, andadvantages of the invention are apparent from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 depicts one embodiment of a conventional raised floor layout of acomputer installation comprising multiple electronics racks;

FIG. 2 is a cross-sectional elevational view of one embodiment of anelectronics rack comprising, in one embodiment, one or more electronicsubsystems configured to accommodate one or more field-replaceable unitswhich may employ latching mechanisms, in accordance with one or moreaspects of the present invention;

FIG. 3 depicts one embodiment of a rack frame and an electronicsubsystem comprising an enclosure configured to receive multiplefield-replaceable units to be latched therein, in accordance with one ormore aspects of the present invention;

FIG. 4 depicts the electronic subsystem of FIG. 3, and illustrates oneembodiment of a field-replaceable unit (FRU), to be slidably docked intoa respective FRU-receiving slot in the enclosure, in accordance with oneor more aspects of the present invention;

FIG. 5A is an enhanced, partial depiction of the electronic subsystem ofFIG. 4, with one field-replaceable unit thereof partially inserted intoa respective FRU-receiving slot in the enclosure, in accordance with oneor more aspects of the present invention;

FIG. 5B depicts the electronic subsystem of FIG. 5A, with thefield-replaceable unit positioned within the respective FRU-receivingslot of the enclosure and the pivotable latch in open position, startingto be pivoted towards a vertical, latched position, in accordance withone or more aspects of the present invention;

FIG. 5C is a partial, cut-away view of the latch, field-replaceableunit, and enclosure of FIG. 5B, showing the latch about to engage aspring member below the FRU-receiving slot in the enclosure within whichthe field-replaceable unit is being docked, in accordance with one ormore aspects of the present invention;

FIG. 5D depicts positioning of spring members within recesses orhousings in the enclosure beneath respective FRU-receiving slots of theelectronic subsystem enclosure of FIGS. 5A-5C, in accordance with one ormore aspects of the present invention;

FIG. 5E is a partial depiction of the pivotable latch initially engagingthe spring member of the latch mechanism, with the spring member shownundeflected position, in accordance with one or more aspects of thepresent invention;

FIG. 5F depicts the partial assembly of FIG. 5E, with the latch pivotedto a latched position, and showing the spring member deflected, inaccordance with one or more aspects of the present invention;

FIG. 6A is a top plan view of one embodiment of a field-replaceable unitdocked and latched within a respective FRU-receiving slot in theenclosure of the electronic subsystem of FIG. 4, in accordance with oneor more aspects of the present invention; and

FIG. 6B is a top plan view of the electronic subsystem of FIGS. 4-6A,with six field-replaceable units docked and latched therein andillustrating coupling of first connectors of the field-replaceable unitsto respective second connectors mounted to, for instance, a mid planedisposed within the enclosure, in accordance with one or more aspects ofthe present invention.

DETAILED DESCRIPTION

As used herein, the terms “electronics rack”, and “rack” are usedinterchangeably, and unless otherwise specified include any housing,frame, rack, compartment, blade server system, etc., having one or morecomponents of a computer system or electronics system, and may be, forexample, a stand-alone computer server unit having high, mid or low endprocessing capability. In one embodiment, an electronics rack maycomprise at least one electronic subsystem, one or more of whichaccommodate one or more field-replaceable units. “Electronic subsystem”refers to any sub-housing, enclosure, blade, book, drawer, node,compartment, etc., having one or more electronic components disposedtherein. An electronic subsystem of an electronics rack may be movableor fixed relative to the electronics rack. As one example, one or moreelectronic subsystems within the electronics rack may be server unitsrequiring additional input/output, control, and/or computer storagecapability. As one specific example, the electronics rack may be an ITEnterprise Computer System, implemented, for example, employing System zserver units, or System p server units, offered by InternationalBusiness Machines Corporation. System z and System p are trademarks ofInternational Business Machines Corporation, of Armonk, N.Y.

Further, as used herein, “enclosure” comprises any housing, chassis,frame, container, etc., configured to accommodate one or more componentsof, for example, a computer system, an electronic system, or electronicsubsystem. Further, “field-replaceable unit” is used herein to compriseany insertable, removable, and/or replaceable component, such as amodular component, which may be docked to or undocked from an enclosure.Note that the input/output and control sleds or assemblies discussedherein present only two examples of a field-replaceable unit with whichthe disclosed latching mechanism may be employed. Still further, a“connector” refers to any connect structure or assembly employed torender the field-replaceable unit operable within the enclosure, and maycomprise an electrical, electronic or communication connector, etc.

Reference is made below to the drawings, which are not drawn to scalefor ease of understanding, wherein the same reference numbers usedthroughout different figures designate the same or similar components.

FIG. 1 depicts a raised floor layout of a data center 100 typical in theprior art, wherein multiple electronics racks 110 are disposed in one ormore rows. A data center such as depicted in FIG. 1 may house severalhundred, or even several thousand microprocessors. In the arrangementillustrated, chilled air enters the computer room via perforated floortiles 160 from a supply air plenum 145 defined between the raised floor140 and a base or sub-floor 165 of the room. Cooled air is taken inthrough louvered or screened doors at the front (i.e., air inlet sides120) of the electronics racks and expelled through the back (i.e., airoutlet sides 130) of the electronics racks. Each electronics rack 110may have one or more air moving devices (e.g., fans or blowers) toprovide forced inlet-to-outlet airflow to cool the electronic componentswithin the drawer(s) of the rack. The supply air plenum 145 providesconditioned and cooled air to the air-inlet sides of the electronicsracks via perforated floor tiles 160 disposed in a “cold” aisle of thecomputer installation. The conditioned and cooled air is supplied toplenum 145 by one or more air conditioning units 150, also disposedwithin the data center 100. Room air is taken into each air conditioningunit 150 near an upper portion thereof. This room air comprises in partexhausted air from the “hot” aisles of the computer installation definedby opposing air outlet sides 130 of the electronics racks 110.

FIG. 2 is an elevational representation of one embodiment of a anelectronics rack 110. In the embodiment shown, electronics rack 110includes a plurality of electronic subsystems 201, which (in theembodiment illustrated) are air-cooled by cool air 202 ingressing vialouvered air inlet door 210, and exhausting out louvered air outlet door211 as hot air 203. Electronics rack 110 also includes (in oneembodiment) at least one bulk power assembly 204. One or more electronicsubsystems 201 include, in one example, one or more processors,associated memory, input/output adapters, controllers, and disk storagedevices. Also illustrated in FIG. 2 is an I/O and disk expansionsubsystem 205, which includes, in one detailed example, PCIe card slots,flexible service processor (FSP) slots, or disk drivers for one or moreelectronic subsystems of the electronics rack. Note that I/O and diskexpansion subsystem 205 could be disposed anywhere within electronicsrack 110, with the positioning shown in FIG. 2 being provided as oneexample only. For example, the I/O and disk expansion subsystem 205could alternatively be disposed in the middle of the electronics rack,if desired.

In one rack example, a three-phase AC source feeds power via an AC powercord 206 to bulk power assembly 204, which transforms the supplied ACpower to an appropriate DC power level for output via distributioncables 207 to the plurality of electronics subsystems 201. AC power cord206 supplies, in one example, three phase electrical power. The numberand type of electronic subsystems installed in the electronics rack arevariable and depend on customer requirements for a particular system.

As noted initially, field-replaceable units have the advantage of beingable to be readily added, removed and/or replaced in a system, withouthaving to send the entire system to a repair facility. Further, themodular nature of field-replaceable units allows for tailoring of systemconfiguration and subsequent system expansion as needed for a particularapplication. For example, a portion of an electronic subsystem enclosuremay be configured to accommodate an expandable number of input/outputand/or control assemblies as field-replaceable units.

Referring collectively to FIGS. 3-4, in one embodiment, an electronicsystem may comprise a rack frame 300, which accommodates a plurality ofelectronic subsystems, with one electronic subsystem 310 beingillustrated, by way of example. Electronic subsystem 310 comprises oneor more enclosures 311 configured to accommodate, at least in part, aplurality of field-replaceable units 400 (FIG. 4), which slidably dockwithin respective field-replaceable unit (FRU)-receiving slots 401 at,in this example, one end of enclosure 311. In FIG. 4, the cover ofelectronics enclosure 311 has been partially removed to expose (in thisembodiment) multiple subsystems with multiple field-replaceable units.

Disclosed herein is a latch mechanism 405 (FIG. 4) which facilitatessecure, positive pressure latching of a field-replaceable unit 400within an FRU-receiving slot 401 of enclosure 311, as described furtherbelow. This latch mechanism 405 is disposed at a first side or end 407of field-replaceable unit 400. A connector assembly may also be providedcomprising at least one first connector 410 at a second side or end 408of the field-replaceable unit 400, and at least one second connector 610(FIGS. 6A & 6B) associated with enclosure 311, for example, mounted to amid-plane 600 within the enclosure (see FIGS. 6A & 6B). With slidabledocking of field-replaceable unit 400 within an FRU-receiving slot 401,contacts within the at least one first connector 410 electricallyconnect to respective contacts within the at least one second connector610 of the connector assembly, thereby ensuring operational coupling ofthe field-replaceable unit 400 within the electronic subsystem 310.

Note that the depicted subsystems with six vertically-inserted,field-replaceable units, is presented by way of example only. Also notethat latch mechanism 405 may be employed with each field-replaceableunit, or only selected field-replaceable units, depending upon theimplementation. In general, the latch mechanism disclosed herein may beemployed with any unit where a positive pressure on the unit directedfrom a first side towards a second side thereof is desired with latchingof the unit within the enclosure. This positive pressure advantageouslyensures fixed mechanical and electrical connection of, for example, theat least one first connector and the at least one second connector of aconnector assembly. More particularly, positive pressure advantageouslyensures, for example, that during shipping or operation, any vibrationof the electronic subsystem does not cause connector contacts to move inrelation to each other, which might otherwise cause wearing of thecontacts, and possibly result in failure or intermittent failure of theelectronic subsystem. Further, the latch mechanism disclosed hereinadvantageously facilitates the addition, removal and/or replacement of aunit within a system. For example, the latch mechanism can facilitatein-field upgrading of a system through the ready addition of furtherunits to the system.

Referring collectively to FIGS. 5A-5F, latch mechanism 405 comprises, inone embodiment, a pivotable latch 500 coupled to a field-replaceableunit 400 via a pivot 505 disposed closer to a first end 501 of pivotablelatch 500 than a second end 502 thereof. FIG. 5A depicts slidableinsertion (or removal) of field-replaceable unit 400 into acorresponding FRU-receiving slot in enclosure 311. In this depiction,pivotable latch 500 of the partially inserted field-replaceable unit isshown in open position. In FIG. 5B, the field-replaceable unit 400 issubstantially docked within the corresponding FRU-receiving slot, but isyet to be fully connected and latched into place within theFRU-receiving slot. In this figure, pivotable latch 500 is shownpartially pivoted from open position towards latched position.

As shown in the enlarged, partial cross-sectional depiction of FIG. 5C,in one embodiment, first end 501 of latch 500 may include an enlargedregion with a first surface 510 and a second surface 511 defined, forinstance, via a substantially U-shaped recess or cut-out in an enlargedregion of latch 500 at first end 501 thereof. First contact surface 510may be disposed and configured as a latch stop to physically contact afront surface of enclosure 311 when the unit is docked and the latch isin the open position, and second surface 511 may be disposed andconfigured to engage a portion of a spring member 520, such as a base521 of spring member 520, which in this embodiment, is disposed withinan appropriately-configured recess 525 or space associated withenclosure 311.

By way of example, FIG. 5D depicts six spring members 520 disposedwithin corresponding recesses 525 in enclosure 311. These recesses andspring members are, in the depicted embodiment, aligned beneath sixcorresponding FRU-receiving slots of the enclosure (see FIGS. 4-5B) sothat the respective pivotable latches of the latch mechanisms associatedwith the field-replaceable units may engage and deflect the respectivespring member with rotating of the latch from an open position to alatched position during latching of the respective unit within theenclosure.

FIGS. 5E & 5F depict in greater detail one embodiment of spring member520, with the spring member shown un-deflected in FIG. 5E, and deflectedin FIG. 5F (with reactive energy stored therein). As noted, in oneembodiment, base 521 of spring member 520 is engaged by second surface511 at first end 501 of pivotable latch arm 500 with rotating of thelatch arm from open position to a latched position during docking of thefield-replaceable unit within the respective FRU-receiving slot of theenclosure. As second surface 511 engages base 521, spring member 520deflects due to the pulling force acting upon it in a direction F₁. Thispulling results in a reactive force which is translated through thepivotable latch towards a second side of the unit (opposite to the firstside thereof) with latching of the unit within the enclosure.

In the embodiment illustrated, spring member 520 is, for instance, ametal tension spring with a first curved spring end 522 and a secondcurved spring end 523. Respective contact surfaces 530, 531 are part ofor associated with enclosure 311, and may comprise, for instance, platesegments which are physically, slidably contacted by the respectivefirst and second curved spring ends, 522, 523 during deflection of thespring member due to latch 500 pulling on base 521 thereof. In theembodiment illustrated, spring member 520 extends from base 521 pastcontact surface 530 and curves back thereto so that first curved springend 522 is (for instance) in slidable, physical contact with firstcontact surface 530, and extends from base 521 past second contactsurface 531 and curves back thereto such that, as the spring deflects,second curved spring end 523 is in (for instance) slidable, physicalcontact with second contact surface 531. In this configuration, springmember 520 is substantially a G-shaped, curved spring member (which isinverted in the plan view depicted).

As illustrated in FIG. 5F, with drawing or pulling of base 521 indirection F₁, the spring deflects with first and second curved springends 522, 523 sliding (in one embodiment) in opposite directionsrelative to the respective contact surfaces 530, 531, storing energy inthe spring member, which provides a reactive force that is translatedalong the vertical length of pivotable latch 500 against the first sideof field-replaceable unit 400 when latched, thereby providing a positivepressure on the field-replaceable unit by the pivotable latch and springassembly. This positive pressure is directed towards the second side ofthe unit, that is, in a direction opposite to direction of force F₁applied to the spring. This positive pressure is maintained, in part,via actuation of a releasable catch (e.g., clip) 503 (see FIGS. 5A & 5B)at second end 502 of pivotable latch 500 to engage an appropriatesurface, structure, etc., associated with enclosure 311. For instance,releasable catch 503 could engage a lip near a front edge of enclosure311 above the respective FRU-receiving slot into which thefield-replaceable unit is being slidably inserted. The positive pressure(or pre-load) facilitates operative docking of the field-replaceableunit within the FRU-receiving slot through, in part, connection of thefirst and second connectors of a connection assembly associated with thefield-replaceable unit and the enclosure, which is illustrated furtherbelow with respect to FIGS. 6A & 6B.

FIGS. 6A & 6B are plan depictions of a single latched, field-replaceableunit and a plurality of latched, field-replaceable units, respectively,of the electronic subsystem described above in relation to FIGS. 3-5F.In this example, six field-replaceable units 400 are operationallydocked within respective, vertically aligned FRU-receiving slots of theelectronics enclosure 311. Referring to FIG. 6A, one field-replaceableunit 400 is shown in docked position, with latch mechanism 405 inlatched position, at first side 407 of the field-replaceable unit 400,and with first connector(s) 410 at second side 408 operatively coupledto second connectors 610 residing on, for example, a mid-plane board 600disposed within enclosure 311 of the electronic subsystem. In FIG. 6B,six field-replaceable units 400 are shown operationally docked withinrespective FRU-receiving slots of the electronics enclosure, with thefirst connector(s) 410 thereof operatively coupled to respective secondconnectors 610 coupled to, or residing on, a board, such as a mid-planeboard of the electronic subsystem.

As illustrated in FIG. 6A, latch mechanism 405 includes catch 503, whichphysically engages a respective surface or edge of enclosure 311 tosecure the field-replaceable unit in latched position, and in doing so,allow for a force to be applied along the face or first side of theunit, due to the reactive force resulting from deflection of the springmember. In one example, catch 503 could extend through an appropriatelysized opening in enclosure 311 to engage an appropriate latching surfaceor edge of the enclosure, to hold the pivotable latch in vertical,latched position, as illustrated in FIGS. 4, 5A & 6A.

To summarize, disclosed herein is a latch mechanism for latching a unitwithin an enclosure. The latch mechanism includes a pivotable latchcoupled to the unit via a pivot, the pivot being disposed at a firstside of the unit; and a spring member associated with the enclosure, andengaged by a first end of the pivotable latch with rotating of the latchfrom an open position to a latched position during latching of the unitwithin the enclosure. The pivotable latch includes the first end asecond end, and the pivot is disposed closer to the first end than thesecond end thereof. In one embodiment, the pivotable latch is anon-compliant latch, such as an elongate, hard plastic arm. Rotating ofthe latch from the open position to the latched position during latchingof the unit within the enclosure results in the latch engaging anddeflecting the spring member. This engaging and deflection of the springmember facilitates provision of a positive pressure by the latchmechanism on the unit via the pivotable latch engaging a first side ofthe unit. The positive pressure is translated towards a second side ofthe unit opposite to the first side thereof with latching of the unitwithin the enclosure.

In one embodiment, the spring member is a deflectable spring member,such as a tension spring member, with a portion (e.g., a base) thereofengaged by the first end of the pivotable latch with rotating of thelatch from the open position to the latched position during latching ofthe unit within the enclosure. For instance, the first end of thepivotable latch may pull on the spring member in a direction opposite toa direction of the positive pressure on the unit directed towards thesecond side of the unit with latching of the unit within the enclosure.

The spring member may include a first spring end and a second springend, wherein the first and second spring ends engage respective contactsurfaces associated with the enclosure, and slide relative to therespective contact surfaces with pulling of the spring member by thelatch during latching of the unit within the enclosure. In one example,the first spring end and the second spring end of the spring membercomprise a first curved spring end and a second curved spring end,respectively, which slidably move in different directions withdeflection of the spring member by the latch.

As one specific example, the spring member may be a substantiallyG-shaped, curved spring member, with the portion of the spring memberengaged by the latch being, for instance, a flat base portion of thesubstantially G-shaped, curved spring member. For instance, the springmember may extend from the base past a first contact surface of therespective contact surfaces, and curve back towards the first contactsurface, with the first curved spring end slidably contacting the firstcontact surface, and the spring member may extend from the base past asecond contact surface of the respective contact surfaces, and curveback towards the second contact surface, with the second curved springend slidably contacting the second contact surface.

In implementation, the spring member may be disposed within a recess inthe enclosure or a structure affixed to the enclosure, for instance,above or below a unit-receiving slot in the enclosure into which theunit is inserted and latched. Note in this regard that, althoughdepicted as being below the unit-receiving slot, the spring memberdisclosed herein could be above the unit-receiving slot, with the latcharm lifting up in an open position, and being pivoted downwards into alatched position, that is, in another embodiment. As noted, thepivotable latch includes a releasable catch adjacent to the second endthereof, which is operable to engage, for instance, a surface orstructure associated with the enclosure, to facilitate latching of theunit within the enclosure, with the positive pressure being maintainedon the unit by the pivotable latch. For instance, the catch could extendthrough a respective opening in the enclosure to engage an appropriatelatching surface or edge of the enclosure.

In one embodiment, at least one first connector of a connector assemblyis disposed at the second side of the unit, and the positive pressureapplied across the unit with latching of the unit within the enclosurefacilitates secure coupling of the at least one first connector to atleast one second connector associated with the enclosure. For instance,the at least one second connector may be disposed on a board, such as amid-plane of an electronic assembly within the enclosure. As oneexample, the unit may be a field-replaceable unit, the enclosure anelectronics enclosure, and the spring member a tension spring disposedwithin a recess within the enclosure below a unit-receiving slot of theenclosure into which the unit is inserted and latched.

Advantageously, the positive pressure or pre-load applied by the latchmechanism is designed to, in part, ensure fixed mechanical andelectrical connection of, for example, at least one first connectorassociated with the field-replaceable unit, and at least one secondconnector associated with, for instance, a back plane or mid-planewithin the enclosure. More particularly, this positive pressure mayadvantageously ensure, for example, that during shipping or operation,any vibration of the electronic subsystem does not cause connectorcontacts to move in relation to each other, which might otherwise causewearing of the contacts (e.g., wearing of a plating thereon), andpossibly result in failure or intermittent failure of the electronicsubsystem. Still further, the latch mechanism disclosed hereinadvantageously provides positive pressure along the first side of thefield-replaceable unit, towards a docked or latched position of the unitwithin the corresponding FRU-receiving slot, without use of anycomponents which would require an operator to use a tool.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprise” (andany form of comprise, such as “comprises” and “comprising”), “have” (andany form of have, such as “has” and “having”), “include” (and any formof include, such as “includes” and “including”), and “contain” (and anyform contain, such as “contains” and “containing”) are open-endedlinking verbs. As a result, a method or device that “comprises”, “has”,“includes” or “contains” one or more steps or elements possesses thoseone or more steps or elements, but is not limited to possessing onlythose one or more steps or elements. Likewise, a step of a method or anelement of a device that “comprises”, “has”, “includes” or “contains”one or more features possesses those one or more features, but is notlimited to possessing only those one or more features. Furthermore, adevice or structure that is configured in a certain way is configured inat least that way, but may also be configured in ways that are notlisted.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below, if any, areintended to include any structure, material, or act for performing thefunction in combination with other claimed elements as specificallyclaimed. The description of the present invention has been presented forpurposes of illustration and description, but is not intended to beexhaustive or limited to the invention in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the invention.

What is claimed is:
 1. A method comprising: providing a pivotable latchcoupled to a unit via a pivot, the pivot being disposed at a first sideof the unit, and the unit to be latched within an enclosure; andproviding a spring member associated with the enclosure and separatefrom the pivotable latch, the spring member being contacted by andhaving a tension force applied thereto by, a first end of the pivotablelatch with rotating of the pivotable latch from an open position to alatched position during latching of the unit within the enclosure, thepivotable latch comprising the first end and a second end, the pivotbeing disposed closer to the first end than the second end thereof, andthe rotating of the pivotable latch from the open position to thelatched position during latching of the unit within the enclosureresulting in the pivotable latch contacting the spring member anddeflecting a first end and a second end of the spring member furtherapart, in opposite directions relative to respective contact surfaces ofthe enclosure contacted by the first end and the second end of thespring member, thereby facilitating provision of a positive pressure onthe unit by the pivotable latch directed towards a second side of theunit opposite to the first side thereof with latching of the unit withinthe enclosure.
 2. The method of claim 1, wherein the spring membercomprises a deflectable spring member with a portion thereof physicallycontacted by the first end of the pivotable latch with rotating of thepivotable latch from the open position to the latched position duringlatching of the unit within the enclosure, the first end of thepivotable latch pulling on the spring member in a direction opposite toa direction of the positive pressure on the unit directed towards thesecond side of the unit with latching of the unit within the enclosure.3. The method of claim 2, wherein the first end and the second end ofthe spring member physically engage the respective contact surfacesassociated with the enclosure and slide relative to the respectivecontact surfaces with pulling of the spring member by the pivotablelatch during latching of the unit within the enclosure.
 4. The method ofclaim 3, wherein the first end and the second end of the spring membercomprise a first curved spring end and a second curved spring end,respectively, and wherein the first and second ends slidably deflect inopposite directions on the first and second contact surfaces withpulling of the spring member by the pivotable latch during latching ofthe unit within the enclosure.
 5. The method of claim 4, wherein theportion of the spring member engaged by the pivotable latch is a base ofthe spring member, and the spring member extends from the base past afirst contact surface of the respective contact surfaces, and curvesback towards the first contact surface with the first curved spring endslidably contacting the first contact surface, and the spring memberextends from the base past a second contact surface of the respectivecontact surfaces, and curves back towards the second contact surfacewith the second curved spring end slidably contacting the second contactsurface.
 6. The method of claim 3, wherein the spring member is asubstantially G-shaped, curved spring member, with the portion of thespring member engaged by the pivotable latch being a flat base portionof the substantially G-shaped, curved spring member.
 7. The method ofclaim 3, wherein the spring member is disposed within a recess withinthe enclosure below a unit-receiving slot of the enclosure into whichthe unit is inserted and latched.
 8. The method of claim 1, whereinproviding the pivotable latch further comprises providing a catch at thesecond end thereof, the catch engaging a surface of the enclosure withlatching of the unit within the enclosure to facilitate the latching ofthe unit within the enclosure, with the positive pressure beingmaintained on the unit by the pivotable latch.
 9. The method of claim 1,wherein at least one first connector is disposed at the second side ofthe unit, and the positive pressure applied across the unit withlatching of the unit within the enclosure facilitates secure coupling ofthe at least one first connector to at least one second connectorassociated with the enclosure.
 10. The method of claim 1, wherein theunit is a field-replaceable unit, the enclosure is an electronicsenclosure, and the spring member comprises a tension spring disposedwithin a recess within the enclosure below a unit-receiving slot of theenclosure into which the unit is inserted and latched.
 11. A method offacilitating secure latching of a field-replaceable unit (FRU) within anenclosure, the method comprising: providing a latch mechanism tofacilitate secure latching of the field-replaceable unit within theenclosure, the latch mechanism comprising: a pivotable latch coupled tothe field-replaceable unit via a pivot, the pivot being disposed at afirst side of the field-replaceable unit; and a spring member associatedwith the enclosure and separate from the pivotable latch, the springmember being contacted by, and having a tension force applied theretoby, a first end of the pivotable latch with rotating of the pivotablelatch from an open position to a latched position during latching of thefield-replaceable unit within the enclosure, the pivotable latchcomprising the first end and a second end, the pivot being disposedcloser to the first end than the second end thereof, and the rotating ofthe pivotable latch from the open position to the latched positionduring latching of the field-replaceable unit within the enclosureresulting in the pivotable latch contacting the spring member anddeflecting a first end and a second end of the spring member fartherapart, in opposite directions relative to respective contact surfaces ofthe enclosure contacted by the first end and the second end of thespring member, thereby facilitating provision of a positive pressure onthe field-replaceable unit by the pivotable latch directed towards asecond side of the field-replaceable unit opposite to the first sidethereof with latching of the field-replaceable unit within theenclosure.
 12. The method of claim 11, wherein the spring membercomprises a deflectable spring member with a portion thereof physicallycontacted by the first end of the pivotable latch with rotating of thepivotable latch from the open position to the latched position duringlatching of the field-replaceable unit within the enclosure, the firstend of the pivotable latch pulling on the spring member in a directionopposite to a direction of the positive pressure on the unit directedtowards the second side of the unit with latching of the unit within theenclosure.
 13. The method of claim 12, wherein the first end and thesecond end of the spring member physically engage the respective contactsurfaces associated with the enclosure and slide relative to therespective contact surfaces with pulling of the spring member by thepivotable latch during latching of the unit within the enclosure. 14.The method of claim 13, wherein the portion of the spring member engagedby the pivotable latch is a base of the spring member, the first end andthe second end of the spring member comprise a first curved spring endand a second curved spring end, respectively, and the spring memberextends from the base past a first contact surface of the respectivecontact surfaces, and curves back towards the first contact surface withthe first curved spring end slidably contacting the first contactsurface, and the spring member extends from the base past a secondcontact surface of the respective contact surfaces, and curves backtowards the second contact surface with the second curved spring endslidably contacting the second contact surface.